The invention concerns methods and an apparatus for spraying portions of an air-improving substance in a room, in particular in a washroom.
Countless proposals are already known for improving air, in particular, in washrooms, by spraying a deodorizing and/or fragrant substance. These proposals range from spray cans which are fitted to the door and which are actuated when the door is opened or closed (for example GB 411 055 A) to programmable dispensers (for example U.S. Pat. No. 6,267,297 B) in which spray sequences which take place in accordance with various selectable criteria can be predetermined. Those dispensers have adjusting options for the beginning and the end of the spray sequences, for the duration of the time intervals in respect of the spray procedures, for daytime or night operation and so forth, and are provided with an electrical spray knob actuating means, an electronic (time) control, a voltage supply, an illumination sensor, and a device which monitors exhaustion of the fragrance. The number of users and user frequency are in that case only limitedly taken into consideration. They are also detected when washrooms are used without daylight by individual people as switching on the lighting leads to the presumption of a user.
In public washrooms, particularly when there is a high number of users and a fluctuating user frequency, the known apparatuses are unsatisfactory. The spray operations should take place whenever they are necessary, in which respect spray operations should be avoided when users are present in order not to spray the users. A time control cannot establish the presence of one or more users and a brightness control cannot ascertain the number of users.